The World Health Organisation estimates that approximately 466 million people worldwide suffer from disabling hearing loss. While many people accept that hearing loss is a natural part of the ageing process, there are in fact many other risk factors for hearing loss.
Today’s article endeavours to highlight risk factors for hearing loss, including, but not limited to, certain types of medication, cancer, smoking, ear candling, and diabetes. Continue reading to learn more about common hearing loss factors.
In a study conducted by the United States National Institutes of Health (NIH), diabetic participants were found to be more than twice as likely to have mild to moderate hearing loss than those without the disease. Further research supported these findings concluding that diabetics are more likely to have hearing loss, regardless of their age.
Adults with prediabetes, where the individual’s blood glucose is above the normal range but not yet high enough for a diabetes diagnosis, have a 30 percent higher rate of hearing loss compared to those with blood sugar levels in the normal range. While it is not completely understood why diabetes impacts hearing, it has long been suspected that high blood glucose levels cause damage to the small blood vessels in the inner ear.
The hair cells in the inner ear are responsible for translating the noise our ears collect into electrical impulses, which they send along the auditory nerve to the brain to interpret as recognisable sound. Once the damaged hearing is permanently affected as these hair cells do not regenerate.
Substances that are poisonous to the ear, and specifically to parts of the cochlea or auditory nerve, are referred to as “ototoxic.” The word comes from a combination of two Latin words: Oto, which translates to “ear”, and toxicity, which translates to “poisoning”.
One of the most common sources of ototoxicity are agents used in cancer treatments, including platinum‐based chemotherapy, radiation and surgery involving the ear, certain antibiotics, and loop diuretics. While the main aim of cancer treatment is to prolong the life of the patient, commonly reported side effects from the treatment include hearing loss and tinnitus.
Oncologists will always do their utmost to mitigate ototoxic exposure during treatment, but when aggressive treatment is required then monitoring of hearing thresholds should occur before, during, and after treatment.
As cancer treatments are now more successful, with cancer patients living longer, identification of hearing loss and subsequent hearing loss treatment (e.g. hearing aids) could improve the patient’s quality of life post-cancer.
Ear wax is a natural byproduct of the ear. Anatomically the ear is designed to be self-cleaning, due to epithelial (i.e. skin) migration and jaw movement. Wax problems only arise due to impaction as a result of a narrowing of the ear canals, use of hearing aids or earplugs, or the use of cotton buds.
When the wax becomes impacted, ear syringing is the most common form of removal as this can be readily performed by a general practitioner in a medical practice. An article in the Australian Family Physician journal, published by The Royal Australian College of General Practitioners recommended that irrigation, or ear syringing, “should be performed only after taking a full history, doing an ear examination and explaining the potential complications to the patient”.
The process of ear syringing involves the gentle irrigation of the ear canal using sterile water or saline. Potential complications include abrasion to the skin of the ear canal, tympanic membrane perforation, tinnitus, dizziness or vertigo, and infection.
Patients with these complications may need audiology treatments and consider onward referral to an ENT specialist. So, while ear syringing is regularly considered the treatment of choice for wax removal due to patient access to services, and is usually effective and safe, complications including hearing loss can arise.
The practice of ear candling has been advertised as a remedy for many conditions, including earwax removal, the treatment of ear infections, relief from sinus pain, reduction in tinnitus intrusion and relief from vertigo.
Ear candling is usually performed by a practitioner of alternative medicine, but ear candles can be purchased in some pharmacies for ‘at home use’. The process of ear candling involves placing a hollow candle into the external auditory canal. The candle is then lit and burned for approximately 15 minutes, with a brown waxy substance left in the candle stub at completion.
A scientific review of ear candling outlined the two main theories of how ear candling might work:
The researchers conducted a small clinical trial to disprove the two hypotheses by performing ear candling with otoendoscopy photographs taken before and after the procedure.
The photos showed that no ear wax was removed, and that candle wax was deposited into the external auditory canals. They concluded that ear candling was associated with considerable hearing loss risk and that there was no evidence to suggest ear candling as an effective treatment for any condition.
Further, a survey of otolaryngologists identified a range of ear injuries that could result from ear candle use, including hearing loss. Perhaps the age-old adage “nothing smaller than your elbow in your ear” should continue to be observed.
The health risks associated with smoking are well-documented, but less known is that this vice is also a risk factor for hearing loss. A research team from Japan found that smokers were 60 percent more likely to develop hearing loss than their non-smoking peers. “The more one smokes, the higher the risk of hearing loss,” concluded researcher Huanhuan Hu of the National Center for Global Health and Medicine in Tokyo.
However, those exposed to passive smoke were not exempt from the risk of developing hearing loss, with results showing they were still 28 percent more likely to have hearing problems. Thus, modification of smoking habits might prevent or delay age-related declines in hearing sensitivity.
It is thought that stress might also be a risk factor for hearing loss. When our bodies respond to stress, we overproduce a hormone called adrenaline which can reduce blood flow to the ears affecting hearing. When daily stress builds up it might disturb blood circulation throughout the body, and without a constant blood flow, the hair cells can become damaged leading to hearing loss.
There is an increasing amount of research that suggests cardiovascular disease (CVD) is a risk factor for hearing loss. CVD is a collective term for diseases of the heart and blood vessels, and commonly includes diseases such as coronary heart disease, heart failure, cardiomyopathy, congenital heart disease, peripheral vascular disease and stroke.
Essentially, CVD makes it harder for blood to flow through the veins, arteries, and organs of the body. The inner ear is extremely sensitive to blood flow, so if blood flow to this area is inadequate, interrupted, or the vessels suffer trauma, this can result in damage to the inner ear nerves which has a direct impact on the ability to hear.
While age and occupational noise exposure are commonly recognised as the main risk factors for hearing loss they are by no means the only risk factors. This article has highlighted many other risk factors including the effects of certain medication, smoking, stress and cardiovascular disease.
With a simple health check by your trusted GP, many of these risk factors become manageable or can be completely reduced. If you’re worried that your hearing has already been affected, don’t hesitate to book a hearing test at your local Attune Hearing clinic.