This article discusses the link between hearing loss and cardiovascular disease, and underscores a growing role for audiologists
Introduction: A growing body of research is showing a significant correlation between cardiovascular disease and low-frequency hearing loss. These studies 1) underscore the advantage of obtaining a baseline hearing exam and, 2) indicate a growing need for Audiologists and Physicians to work in partnership for the best health outcome of patients.
Early Studies: Most of the early studies focus on the consequences of decreased blood supply due to cardiovascular disease, and the resulting negative effects on the blood vessel health of the inner ear. The inner ear is studied because it is loaded with blood vessels and extremely sensitive to blood supply, so abnormalities show up here before they can be found elsewhere. These studies indicate that a healthy cardiovascular system promotes healthy hearing, but inadequate blood supply and resulting damage to the blood vessels of the inner ear can contribute to hearing loss.
New Research: A two-part 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. This study also indicates that low-frequency audiometric patterns (observed on sensitive audiological equipment) can be used to determine the probability and risk for cardiovascular events and cerebrovascular disease such as stroke and transient ischemic attacks (compromised blood supply in the brain). 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 supply before they are revealed in the heart, brain, arteries, kidneys, or eyes, due to the inner ear’s extreme sensitivity to blood supply.
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 ongoing or 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”.
Conclusions: 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 disease.
Audiologists commonly refer patients to Physicians when they suspect medical problems. These studies (and others) should promote a call to action for physicians to refer more patients to Audiologists when they suspect hearing loss. Many Audiologists have Doctor of Audiology (AuD) 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.
About the Author: Dr. Ha-Sheng Li-Korotky is the President and co-founder of Pacific Northwest Audiology (www.pnwaudiology.com), based in Bend, Oregon (see back inside cover). The Doctor is a nationally acclaimed clinician and research scientist, with AuD, PhD, and MD credentials and more than 100 scientific publications.