Clinical Confirmation
These experimental results were confirmed by observations in the population-based Gutenberg Health Study. The researchers analyzed data from 100 patients with heart attack. The lead and senior authors of the study Michael Molitor, MD, and Philip Wenzel, MD, of the University of Mainz, explained, “From our studies, we have learned that exposure to aircraft noise before a heart attack significantly amplifies subsequent cardiovascular inflammation and exacerbates ischemic heart failure, which is favored by inflammation-promoting vascular conditioning. Our translational results show that people who have been exposed to noise in the past have a worse course if they experience a heart attack later in life.”
Study participants who had experienced a heart attack in their medical history had elevated levels of C-reactive protein if they had been exposed to aircraft noise in the past and subsequently developed noise annoyance reactions (0.305 vs 1.5; P = .0094). In addition, left ventricular ejection fraction in these patients after a heart attack was worse than that in patients with infarction without noise exposure in their medical history (62.5 vs 65.6; P = .0053).
The results suggest that measures to reduce environmental noise could help improve the clinical outcomes of heart attack patients, according to the authors.
Mental Health Effects
Traffic noise also may be associated with an increased risk for depression and anxiety disorders, as reported 2 years ago by the German Society for Psychosomatic Medicine and Medical Psychotherapy. Evolution has programmed the human organism to perceive noises as indicators of potential sources of danger — even during sleep. “Noise puts the body on alert,” explained Manfred E. Beutel, MD, director of the Clinic for Psychosomatic Medicine and Psychotherapy at the University of Mainz. As a result, the autonomic nervous system activates stress hormones such as adrenaline and cortisol, leading to an increase in heart rate and blood pressure. If noise becomes chronic, chronic diseases can develop. “Indeed, observational and experimental studies have shown that persistent noise annoyance promotes incident hypertension, cardiovascular diseases, and type 2 diabetes,” said Dr. Beutel.
Depression Risk Doubled
Among the negative effects of noise annoyance are also mental illnesses, as has become increasingly clear. “Noise annoyance disrupts daily activities and interferes with feelings and thoughts, sleep, and recovery,” said Dr. Beutel. The interruptions trigger negative emotional reactions such as anger, distress, exhaustion, flight impulses, and stress symptoms. “Such conditions promote the development of depression over time,” said Dr. Beutel. This observation was confirmed by the large-scale Gutenberg Health Study using the example of the Mainz population, which suffers to a large extent from noise annoyance because of the nearby Frankfurt Airport. “With increasing noise annoyance, the rates of depression and anxiety disorders steadily increased, until the risks eventually doubled with extreme annoyance,” said Dr. Beutel. Other studies point in the same direction. For example, a meta-analysis found a 12% increase in the risk for depression per 10-dB increase in noise. Another study found an association between nocturnal noise annoyance and the use of antidepressants.
Fine Particulate Matter
According to an evaluation of the Gutenberg Study, people perceive noise annoyance from aircraft noise as the most pronounced, followed by road, neighborhood, industrial, and railway noise. Noise occurs most frequently in urban areas that also produce air pollution such as fine particulate matter. “Fine particulate matter is also suspected of promoting anxiety and depression,” said Dr. Beutel, “because the small particles of fine particulate matter can enter the bloodstream and trigger inflammatory processes there, which in turn are closely related to depression.”
This story was translated from Univadis Germany, which is part of the Medscape professional network, using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.