The Ear is a Window to the Heart: A Modest Argument for a Closer Integration of Medical Disciplines

Though it is generally understood that hearing worsens with advanced age, there remains some debate as to whether the noise exposure history, dietary patterns, general health or genetic makeup of individuals contributes most to this chronic problem. For the past decade, and for the past five years especially, there has been an expansion in the number of published studies looking at modifiable risk factors that may contribute to hearing loss. For instance, there are current studies that show a compelling relationship between acquired hearing impairment and poor cardiovascular fitness [1,2] and hypertension [3]. Additionally, cardio-metabolic disorders [4,5] (e.g., metabolic syndrome, Type 2 diabetes) and high risk behaviors, such as smoking [6], have been implicated in acquired hearing impairments. Conversely, moderate alcohol consumption has been described as a potential protective factor [7].

So, what is the final word on the issue? Does cardiovascular disease cause hearing loss, or not? Is exercise protective of cochlear function, or is it a risk factor? Can hearing loss be an indication, or biomarker, for underlying cardiovascular disease?

What we can say with confidence is that states of disease, whether cardiovascular or cardio-metabolic in nature, which result from patterns of behavior generally linked to poor nutrition, lack of exercise, stress, and smoking, are clearly related to loss of hearing acuity in older adults. Unfortunately, none of the above risk factors are easily modified. Additionally, there is no evidence that reversing cardiovascular risk or disease can reverse the damage that has already been done to the ear.

The picture becomes more dismal when we consider that the current state of health in the U.S. is decreasing. We have all heard of the obesity epidemic and that the estimated life expectancy of upcoming generations, for the first time, is declining [8]. As our society (especially the younger generations) becomes more sedentary and increasingly dependent on calorie dense, nutritionally sparse diets, we are likely to see an expansion of many diseases/disorders, the least of which is hearing loss. According to Zhan et al. [9], in a study of generational differences in hearing loss prevalence, there is evidence that hearing loss is lower in men and women among ‘baby boomers’ compared to previous generations. They offer the explanation that environmental, lifestyle, or other modifiable factors, such as efficacy and widespread use of blood pressure controlling medications; contribute to the current etiology of hearing impairment in older adults [9]. It is arguable, however, that the reduced prevalence of hearing loss in the ‘baby boomers’ compared to their parents’ generation, as noted by Zhan et al., will see a reversal in successive generations.

What the current data shows is that the specialized medical professions, including the specialty of otolaryngology and her allied disciplines, can no longer function in a vacuum. Indeed the patient’s fitness, BMI, dietary patterns, and risky behaviors, such as smoking, can have an extensive impact on hearing, as one example. Other aspects that may be equally affected include vestibular function, sleep quality, airway, and head/neck tumor genesis. One should not argue for a new model of care, but rather, for an enhanced model, where all otolaryngology professionals seek out and maintain collaborations with other specialties, making it a point to routinely engage patients on all aspects of their general health and wellness. Perhaps, with the widespread implementation of electronic health record systems and the increasing popularity of open access journals, a new era in clinical communication and scientific collaboration among the medical specialties can be forged. In addition to a rapid peer review process, the open access model lends itself to enhanced social networking, language translation, and other digital access features that facilitate dissemination of new and otherwise critical information.