MAINZ, GERMANY — An updated evidence review strengthens the concept that exposure to environmental noise from road traffic and aircraft may increase the risk for heart disease and gets at the potential underlying pathophysiologic mechanisms.
Traffic noise has been shown in many studies to increase the risk for heart disease, but the precise mechanisms that lead to noise-induced heart disease have been unclear.
On the basis of their evidence review, Dr Thomas Münzel (Johannes Gutenberg University, Mainz, Germany) and colleagues say it's becoming clear that transportation noise is associated with oxidative stress, vascular dysfunction, autonomic imbalance and metabolic abnormalities—potentially contributing to the development of cardiovascular risk factors, such as arterial hypertension and diabetes, as well as progression of atherosclerosis and increased susceptibility to cardiovascular events.
"Our review includes new studies with respect to epidemiology, noise, and cardiovascular disease with focus on new translational studies trying to explain why noise is causing vascular damage," Münzel told theheart.org | Medscape Cardiology. "I think there is no doubt anymore that chronic noise exposure, in particular nighttime noise, can cause coronary disease, heart failure, stroke, and arterial hypertension."
"New, in particular, are studies demonstrating that even one night of aircraft noise exposure can cause vascular (endothelial) dysfunction in healthy subjects," said Münzel. Nighttime noise has also been shown to decrease sleep quality and increase stress hormone levels.
"In patients with established coronary artery disease, the adverse effects of nighttime noise on vascular function were, as expected, even stronger," Münzel said.
In addition, the authors say a transcriptome analysis of aortic tissues from animals exposed to aircraft noise revealed changes in the expression of genes responsible for the regulation of vascular function, vascular remodeling, and cell death.
Their review was published online February 5 in the Journal of the American College of Cardiology.
The authors also looked at some of the mitigation strategies used around the world. They conclude that strategies such as traffic management and regulation and the development of low-noise tires may help reduce noise, and air traffic curfews help reduce hazardous noise, but other strategies are needed.
The authors also note that many questions remain to be addressed, such as the magnitude and time course of response to coexposure of noise and air pollution; synergistic effects of both exposures on surrogate measures, such as blood pressure and metabolic risk; duration of effect/time course of reversal; impact of low-grade background noise exposure on air pollution exposure effects and vice versa; impact of noise on the circadian rhythm; and the effects on lifestyle (diet, stress, and exercise).
As more of the global population is exposed to detrimental levels of transportation noise, new developments and legislation to reduce noise are important for public health, Münzel told theheart.org | Medscape Cardiology.
He hopes politicians create laws to protect people from environmental stressors and "take into account in particular the new findings concerning noise pollution and cardiovascular disease and to acknowledge noise as a cardiovascular risk factor," he said.
With respect to aircraft noise and airports, "it is important to make new laws and new lower noise limits that protect people living close to airports," Münzel added.
"My wish is that noise is getting now accepted as a cardiovascular risk factor like smoking, diabetes, and high cholesterol, and that this is pinned down also (for example) in the prevention guidelines," Münzel said.
An Emerging Risk Factor
"We have learned in the last several decades that the health effects of noise go well beyond hearing loss," Dr Rick Neitzel (University of Michigan, Ann Arbor) said in an interview. "However, our knowledge related to these other effects is not nearly as great. This paper makes an important contribution to our understanding of the mechanisms of cardiovascular damage resulting from noise exposure.
"As we become increasingly aware of the substantial threat that noise poses to public health, a clear understanding of the mechanisms of damage is critical to efforts focused on minimizing cardiovascular health impacts," added Neitzel, who wasn't involved in the review.
"This is a nice summation of the studies that are out there, both the basic science, epidemiologic studies and some of the other research, and proposing some of the mechanisms by which environmental noise may be leading to cardiovascular disease," Dr William Borden (George Washington University, Washington, DC), member of the American College of Cardiology Task Force on Population Health, told theheart.org | Medscape Cardiology.
Borden, who wasn't involved in the review, said environmental noise is "an emerging risk factor" and this review "strengthens the connection between environmental noise and cardiovascular risk, but it's still an area where more research is needed."
For clinicians and patients, he added, there has to be "an important emphasis and focus on traditional risk factors like smoking cessation, blood pressure control, cholesterol and diabetes management and diet and exercise."
The study had no specific funding. The authors have declared no relevant conflicts of interest.
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Medscape Medical News © 2018
Cite this: Traffic Noise Linked to Increased CVD Risk - Medscape - Feb 09, 2018.