Researchers believe their findings will help doctors identify and treat the onset of hearing impairment for patients at risk of cardiovascular disease
Heart disease is the leading cause of death in the United States, and some risk factors such as hypertension and diabetes are on the rise. A study published in Scientific Reports sheds new light on the issue by tracing how hearing loss is related to cardiovascular disease risk factors, highlighting the heart’s interconnection with bodily senses and opportunities for early treatment.
Rachael Baiduc, an assistant professor at the University of Colorado Boulder and the paper’s lead author, is the director of the Hearing Epidemiology and Research Diagnostics (HEARD) Laboratory, which investigates cardiovascular disease (CVD) risk factors and its relationship with adult-onset hearing impairment and the inner-workings of the ear.
“The inner-ear is actually a delicate structure,” Baiduc says. “It’s really susceptible to any damage from ischemia (inadequate blood supply) and hypoxia (low levels of oxygen in body tissues). It is highly susceptible to any microvascular compromise,” or dysfunction in the circulatory system of small blood vessels.
In collaboration with Eric Vance, a statistician and associate professor at CU Boulder, Baiduc used data from electronic health reviews from thousands of patients at UCHealth to observe connections between CVD risks, such as diabetes, smoking and hypertension, and hearing loss.
“We developed models to understand the connection between these risk factors and hearing loss while we accounted for other potential confounders such as age, body mass index and noise exposure. We tried our best to isolate one risk factor at a time in a clinical population,” Baiduc says.
Isolating CVD risk factors helped narrow down the population of patients who are most susceptible to hearing loss: diabetics, smokers and those with hypertension.
“This study is important for people who have diabetes or hypertension, because it shows that they are at greater risk of developing hearing loss,” Vance says. “Not every person who goes to the doctor gets checked out for hearing, and yet hearing loss is a major problem.”
The study also uncovered that the association between CVD risk factors and hearing loss was more prevalent for men than women—likely because of sociocultural and biological factors—but that the association was found to be significant in both sexes.
“There are sociocultural differences in men and women in terms of their exposure to risk factors for hearing loss as well as cardiovascular disease risks. For example, men are more likely to be smokers than women, and lifestyle factors such as smoking and diet choices do play a role” in CVD risk and hearing loss, Baiduc says.
On the biological side, the study notes that hypertension does not appear as a significant risk factor in women for developing hearing loss. Researchers’ hypothesis for this is that estrogen provides protective effects against toxicity and other potential damages to the ear.
The connection between cardiovascular and hearing health usually surprises experts, but Baiduc and Vance hope their research will make an impact on medical research and health care communities in identifying and treating the onset of hearing loss for populations with CVD risk factors.
Even when I go to conferences and talk to a variety of folks from cardiologists to endocrinologists, a lot of them are not aware of this connection at all between smoking, diabetes and hearing loss. The first step is to educate healthcare professionals and diabetes educators.”
“Even when I go to conferences and talk to a variety of folks from cardiologists to endocrinologists, a lot of them are not aware of this connection at all between smoking, diabetes and hearing loss,” Baiduc says. “So, the first step is to educate healthcare professionals and diabetes educators.”
“In terms of the big picture, just making general practitioners aware of this connection with their patients with one or more of these risk factors and encouraging them to get hearing screenings over time would be really important, especially those with diabetes; that’s the big one right now that stands out,” Baiduc says.
For Vance, who is the director of the Laboratory for Interdisciplinary Statistical Analysis (LISA), their research exemplifies how the collaboration between data analysis and medical research can benefit humanity.
“There are a lot of things about the body that are interrelated that we don’t quite understand. We’re still discovering and learning about ourselves,” Vance says. “It’s really important to have collaboration between statisticians and medical experts, since it allows us to understand from a large collection of patients what’s really going with the human body and why.”
Since their collaboration, Baiduc has published a new study in Laryngoscope Investigative Otolaryngology about the relationship between hearing loss and CVD risk factors in African Americans.