Chronic noise can impact heart health
Exposure to a high level of noise on a regular basis can wreak havoc on the cardiovascular system, according to new research.
The leader of the study was Dr. Azar Radfar, Ph.D., a research fellow at the Massachusetts General Hospital in Boston. The findings will be presented at Scientific Sessions 2018, held by the American Heart Association (AHA) in Chicago, IL.
Dr. Radfar's team found that noise exposure causes an elevated stress response in the human brain.
This can lead to inflammation in the blood vessels, which can cause serious health problems, including a heart attack or stroke.
The research included 499 participants, who were free from cardiovascular disease and cancer at the study's start.
Noise and cardiovascular events
The participants underwent positron emission tomography (PET) and CT scans of their brains and blood vessels. The researchers also looked at the activity of the amygdala, a region of the brain that regulates stress and emotional response.
The team estimated participants' regular exposure to noise by comparing their home addresses with data from the United States Department of Transportation's National Transportation Noise Map, which includes information about levels of roadway and aviation noise.
Years later, the researchers examined the participants' medical records for evidence of cardiovascular events. Of the 499 original participants, 40 had experienced a heart attack or stroke in the 5 years that followed the initial testing.
After analyzing the data, the team discovered that participants with the highest levels of noise exposure also had the most noticeable stress-related brain activity. In addition, they had more inflammation in their arteries.
Increased blood vessel inflammation is a well-established risk factor for heart disease, so finding a link between this inflammation and cardiovascular events was no surprise.
However, participants with the most stress-related brain activity were more than three times as likely to experience a major cardiovascular event, such as a heart attack or stroke.
Even after accounting for other risk factors, such as air pollution, smoking, and diabetes, the team concluded that participants exposed to higher levels of noise pollution had an increased risk of cardiovascular events.
"A growing body of research reveals an association between ambient noise and cardiovascular disease, but the physiological mechanisms behind it have remained unclear," explains Dr. Radfar, adding, "We believe our findings offer an important insight into the biology behind this phenomenon."
