A growing body of research is showing a significant correlation between cardiovascular disease and low-frequency hearing loss. Moreover, the studies underscore a growing need for Audiologists and Physicians to work in partnership for the best health outcome of patients.
Most of the studies focus on the consequences of decreased blood supply due to cardiovascular compromise, and the downstream negative effects on the inner ear blood vessel health. The inner ear is extremely sensitive to blood flow, and there appears to be a strong relationship between the health of the cardiovascular system (heart, arteries, and veins) and hearing. These studies indicate that a healthy cardiovascular system promotes healthy hearing, but inadequate blood flow and resulting damage to the blood vessels of the inner ear can contribute to hearing loss.
A recent study, Audiometric Pattern as a Predictor of Cardiovascular Status: Development of a Model for Assessment of Risk, suggests that low-frequency hearing loss could be a marker for cardiovascular disease rather than a result of the disease, and low-frequency audiometric patterns can be used probabilistically to predict cardiovascular health. An underlying premise of the study is that vascular aspects (decreased blood supply) of cardiovascular disease show up as abnormalities in the condition of inner ear blood flow before they are revealed in the heart, brain, arteries, kidneys, or eyes, due to the inner ear’s extreme sensitivity to blood flow.
Key findings in this study indicate that low-frequency hearing loss could be an early indicator of cerebrovascular disease (an indicator of stroke potential) or a predictor for developing cardiovascular disease. Findings were presented in 2009 at a Combined Otolaryngology Spring Meeting by David R. Friedland, MD, PhD., and published in The Laryngoscope (119:473-486, 2009).
Dr. Friedland summed up the important potential application of the study: “We propose that low-frequency hearing loss is a marker for cardiovascular disease rather than the other way around. Low-frequency hearing loss would thus represent a potential predictor of impending cardiovascular events or underlying disease. We suggest that clinicians may use the audiogram as a sensitive and reproducible screen for cardiovascular compromise”.
Considering the strength of the evidence, researchers conclude that patients with an audiogram pattern of low-frequency hearing loss present a higher risk for cardiovascular events, and that appropriate referrals may be necessary, especially if they have no history of vascular compromise.
Audiologists commonly refer patients to Physicians when they suspect medical problems. These studies (and others which will be highlighted in future articles) should promote a call to action for physicians to refer more patients to Audiologists when they suspect hearing loss. Many Audiologists have AuD academic credentials, significant medical knowledge, and the advanced diagnostic equipment necessary to uncover the potential for underlying medical conditions. In any case, these and other studies suggest an increasing role for Audiologists to support the overall health of patients.