Scientists believe that noise-induced heart disease could be part of the reason heart disease is the number one cause of death in the United States and worldwide. In a new review from the American College of Cardiology (ACC), researchers begin to explain how noise from road traffic, airplanes, trains, and other environmental sources increase the risk of risk factors for heart disease.
Well-studied risk factors for heart disease such as high blood pressure and diabetes contribute toward the development of heart problems like stroke, coronary artery disease, and heart failure. Exposure to transportation noise seems to be making these problems worse. But how? In their new review, ACC experts explain the molecular mechanisms responsible for noise increasing the risk of heart disease.
By analyzing several translational noise studies, researchers connected the dots between dysfunction in the body’s blood vessels and the development of heart disease caused by noise. They also studied the “non-auditory effects of noise” and how they affect the cardiovascular system.
Noise produces a stress response, activating the sympathetic nervous system. This is the part of the nervous system that increases heart rate, blood pressure, breathing rate, and pupil size in preparation for physical and mental activity. Additionally, the stress response increases levels of hormones that promote vascular damage.
Additionally, transportation noise exacerbates the state of existing risk factors for heart disease. Researchers found links between noise and oxidative stress, vascular dysfunction, autonomic imbalance, and metabolic abnormalities. Oxidative stress is a cellular disturbance where reactive oxygen species outnumber antioxidant defenses, leading to tissue damage. The autonomic nervous system, also known as the involuntary nervous system, controls muscles of internal organs, including the heart.
“As the percentage of the population exposed to detrimental levels of transportation noise are rising, new developments and legislation to reduce noise are important for public health,” said lead author Thomas Munzel, MD, from Johannes Gutenberg University in Germany.
Such developments to reduce noise include managing and regulating traffic, producing low-noise tires, and enacting curfews for air traffic, but according to Munzel, that’s not enough.
The present study was published in the Journal of the American College of Cardiology.
Sources: Metabolism, PubMed Health 1, PubMed Health 2, Centers for Disease Control and Prevention, American College of Cardiology
