The inner ear, where sound is converted to electricity (and sent to the brain via the auditory nerve network), is very dependent on healthy circulation. Though very small when compared to other vital organs, it is an energy-intensive part of the body and requires a constant inflow of nutrients.
This is why diabetes, unfortunately, is very much a risk factor for hearing loss. Current research posits that diabetics are two times more likely to have hearing issues than non-diabetics.
Since diabetes inhibits the bloodstream’s ability to transport glucose, a sugar vital to transferring energy to cells, it can prevent the ear from functioning normally. There is also evidence that the elevated levels of blood glucose — diabetes causes glucose to buildup in the blood rather than be transferred to cells throughout the body — damages the blood vessels that are vital to the inner ear.
One fundamental role these blood vessels play is in nourishing the stereocilia, the tiny hair cells that are a crucial part of the inner ear. These hairs cannot regrow or regenerate after being damaged. And a lack of healthy blood flow will damage them.
Diabetes, if untreated, can wreak havoc with much of the body’s functions. It can cause blindness, organ failure, and lead to amputation of extremities.
A 2012 study published in the Journal of Clinical Endocrinology and Metabolism concluded, after evaluating 13 other studies based on over 20,000 subjects, that the higher risk for hearing loss in diabetics was clear and cut across age and other risk factors.
The general advice to diabetics — exercise regularly and keep weight under control — will also lessen the chances of hearing loss. In addition, protecting ears from other risk factors, such as excessive noise, is even more important for a diabetic.