Diabetes and Hearing Loss: 8 Questions - 8 Answers
- Alperen Akbulut
- Jul 13, 2025
- 5 min read
Updated: Jul 20, 2025
It is widely known that diabetes can affect organs such as the eyes, kidneys, and heart; however, its impact on the auditory system is often overlooked. Yet, research shows that diabetes is also closely linked to hearing loss. In this article, we provide short and clear answers to 8 questions about diabetic hearing loss, based on scientific data.
What is Diabetes?
Diabetes (Diabetes Mellitus - DM) is a group of metabolic diseases characterized by high levels of glucose in the blood (hyperglycemia) resulting from defects in insulin secretion, insulin action, or both (Samocha-Bonet et al., 2021). There are two main types: Type 1 diabetes typically leads to absolute insulin deficiency due to autoimmune destruction of pancreatic beta cells. Type 2 diabetes is a progressive disease that usually results from the loss of beta-cell function on the background of long-term insulin resistance (Gioacchini et al., 2023). Gestational diabetes is insulin resistance related to pregnancy and is a strong risk factor for postpartum Type 2 diabetes. In addition to Type 1 and Type 2 diabetes, a rare type of diabetes due to mitochondrial DNA mutations has also been reported to be associated with hearing loss (Samocha-Bonet et al., 2021).
What is the Relationship Between Diabetes and Hearing Loss?
Numerous studies indicate that diabetes is a risk factor for hearing loss (Deng et al., 2023). The prevalence of hearing loss in diabetic patients is higher than in non-diabetics (Gioacchini et al., 2023). While this relationship is complex, there is significant evidence that hearing loss may be a complication of diabetes (Samocha-Bonet et al., 2021). Unlike conductive hearing loss, which affects the ear canal or middle ear, diabetic hearing loss is classified as sensorineural hearing loss (SNHL), affecting the nerve fibers or sensory cells of the inner ear (Deng et al., 2023).
How Can Diabetes Affect the Auditory System?
Although the mechanisms by which diabetes damages the auditory system are not fully clear, several theories have been proposed (Gioacchini et al., 2023). The most significant among these include microvascular damage (damage to small blood vessels), formation of advanced glycation end products, reactive oxidative stress, mitochondrial dysfunction, demyelination of the auditory nerve (loss of the myelin sheath), spiral ganglion loss, and atrophic (shrinking) changes in the cells of the organ of Corti (Samocha-Bonet et al., 2021; Deng et al., 2023). Structures in the inner ear with high vascularization, such as the stria vascularis and spiral ganglion, are particularly susceptible to the effects of hyperglycemia (Deng et al., 2023).
What are the Distinctive Pathological Features of Diabetic Hearing Loss?
Typical pathological changes associated with diabetic hearing loss are primarily seen in the inner ear (Figure 1) (Samocha-Bonet et al., 2021). The spiral modiolar artery (the main vessel supplying blood to the cochlea) may show wall thickening and an increase in lumen diameter (Gioacchini et al., 2023). Atrophy (shrinkage) in the stria vascularis, condensation of cell cytoplasm, swelling of intermediate cells, widening of intercellular spaces, and the formation of cavities in cells can be observed (Samocha-Bonet et al., 2021; Deng et al., 2023). The walls of the vessels of the stria vascularis may also thicken. In the auditory nervous system, atrophy or loss of spiral ganglion cells, loss of afferent nerve fibers, and swelling at the fiber endings can be seen (Deng et al., 2023). In the organ of Corti, damage such as loss or degeneration of outer hair cells and the disappearance of the nuclei of supporting cells may occur (Gioacchini et al., 2023).
How Do Different Types of Diabetes Affect Hearing Loss?
Both Type 1 and Type 2 diabetic patients have been shown to have poorer hearing than normal individuals (Deng et al., 2023). Meta-analyses indicate that the risk of sensorineural hearing loss is significantly higher in both Type 1 and Type 2 diabetic patients compared to control groups (Gioacchini et al., 2023). Some studies suggest that in early-onset Type 1 diabetes, hearing loss may not be apparent on standard audiometry tests in the early stages, but early cochlear damage can be detected with more sensitive tests like otoacoustic emissions (OAEs) (Deng et al., 2023). In patients with Type 2 diabetes, hearing is generally affected across all frequencies but becomes more pronounced at high frequencies (Samocha-Bonet et al., 2021).
What are the Risk Factors for the Development of Diabetic Hearing Loss?
Diabetic hearing loss is influenced by various risk factors such as the duration and severity of diabetes, and the patient's age (Gioacchini et al., 2023). The duration of diabetes is a significant variable affecting the incidence of hearing loss and shows a positive correlation with it (Deng et al., 2023). As the duration of diabetes increases, so does the risk of hearing loss. The severity of diabetes (e.g., glycemic control level, HbA1c levels) is also associated with the risk of hearing loss (Samocha-Bonet et al., 2021). Age is another important factor; hearing thresholds and the prevalence of hearing loss increase with age in both diabetic and non-diabetic individuals, but the effect of age may be more pronounced in diabetic patients (Deng et al., 2023). Other factors, such as noise exposure, can also exacerbate diabetic hearing loss (Gioacchini et al., 2023).
How is Diabetic Hearing Loss Diagnosed?
Audiological assessment methods such as pure-tone audiometry, otoacoustic emissions (OAEs), and auditory brainstem response (ABR) testing are generally used to diagnose diabetic hearing loss (Gioacchini et al., 2023). Pure-tone audiometry measures hearing thresholds at different frequencies. OAEs reflect the condition of the hair cells in the inner ear and can be useful for early detection of damage (Deng et al., 2023). ABR evaluates the electrical activity of the auditory nerve and brainstem pathways and can indicate retrocochlear (beyond the inner ear) involvement. Tests like extended high-frequency audiometry and DPOAEs have been shown to be more sensitive, especially in early stages or in diabetic patients with normal hearing on standard tests (Samocha-Bonet et al., 2021).
Are There Treatment Options for Diabetic Hearing Loss?
Treatment approaches for diabetic hearing loss generally focus on symptom management and controlling the underlying diabetes (Deng et al., 2023; Samocha-Bonet et al., 2021). Good management of diabetes can be important in slowing the progression of hearing loss. There are preliminary studies suggesting that some agents, like antioxidants, can improve hearing function in animal models, but these are not yet proven effective treatments in humans (Gioacchini et al., 2023). Rehabilitative solutions, such as hearing aids, can be used to improve the communication abilities and quality of life for diabetic patients with hearing loss.
References:
Samocha-Bonet, D., Wu, B., & Ryugo, D. K. (2021). Diabetes mellitus and hearing loss: A review. Ageing Research Reviews, 71, 101423. https://doi.org/10.1016/j.arr.2021.101423
Gioacchini, F. M., Pisani, D., Viola, P., et al. (2023). Diabetes Mellitus and Hearing Loss: A Complex Relationship. Medicina, 59(2), 269. https://doi.org/10.3390/medicina59020269
Deng, Y., Chen, S., & Hu, J. (2023). Diabetes mellitus and hearing loss. Molecular Medicine, 29, 141. https://doi.org/10.1186/s10020-023-00737-z
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