By Tosha R. Hodgson, BA, MClSc, Reg. Audiologist
While earlier studies failed to convince, more current research suggests that hearing loss may be an under-recognized complication of diabetes.
One of the fastest growing chronic diseases, diabetes is a chronic metabolic disorder in which blood glucose levels are too high. It is a systemic disease that affects multiple organ systems.
Given that diabetes is a systemic disease, researchers have questioned if the auditory system is affected by diabetes. Studies attempting to link diabetes with hearing loss have not been convincing in the past, often due to the subject pools selected or the designs of the studies. Until recently, conflicting evidence in the literature has deterred acceptance of diabetes-related hearing impairment by researchers and hearing care professionals alike. However, more current research has overcome some previous studies’ shortcomings.
In 2008, Bainbridge et al. investigated if hearing impairment is more prevalent among diabetic adults than non-diabetic adults. In 2011 they examined risk factors of low-/mid-frequency hearing impairment and high-frequency hearing impairment among a nationally representative sample of diabetic adults in the US. They analyzed data from hearing tests administered from 1999 to 2004 to participants in the National Health and Nutrition Examination Survey (NHANES). Results revealed [1,2]:
- A higher occurrence of hearing impairment in diabetic adults than in non-diabetics.
- A greater likelihood of hearing impairment in diabetic adults with low high-density lipoprotein (HDL) cholesterol (known as “good” cholesterol), a history of coronary heart disease, symptoms of peripheral neuropathy, or reported poor health.
- Two-thirds of diabetic subjects had high-frequency hearing impairment.
- Twenty-six percent of diabetic subjects also had low-/mid-frequency hearing impairment.
In 2012, Japanese researchers analyzed the combined results of thirteen previous studies and found impaired hearing was twice as common among people with diabetes compared to non-diabetics and, interestingly, hearing impairment was 2.6 times higher in younger diabetic adults (≤ 60 years old) compared to older adults.
In a press release from the National Institutes of Health (NIH), Catherine Cowie, PhD, of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDKD) stated, “Hearing loss may be an under-recognized complication of diabetes. As diabetes becomes more common, the disease may become a more significant contributor to hearing loss.”
Individuals who have diabetes, are pre-diabetic, or have a family history of diabetes are encouraged to have their hearing assessed, particularly those who are middle-aged. Hearing care professionals should ask clients about any history of diabetes. Physicians, endocrinologists, and other health care providers are encouraged to consider referring diabetic individuals for audiological evaluation. Annual audiological monitoring is recommended for individuals who have diabetes or a family history of the disease.
Any unexplained hearing loss warrants further investigation. Routine hearing evaluations can help identify hearing problems—and potentially more serious health concerns—early so they can be investigated and treated as soon as possible. Eat well, exercise, rest, and don’t forget to test and protect your sensitive hearing.