Recent research has shown that people exposed to airplane noise at night can increase their odds of dying from heart disease within just 2 hours of noise exposure.
A team of Swedish researchers analyzed nearly 25,000 heart disease deaths that occurred in individuals living near Zurich airport (ZRH) and discovered that aircraft noise contributes to approximately 3% of cardiovascular deaths.
In particular, the risk of cardiovascular death also increased by 33% when the noise level at night was between 40dB and 50dB, and increased by 44% with noise level of 55dB or more.
“The takeaway from these findings is that the adaptation and calming of nocturnal noises has been validated,” said senior author Martin Röösli, PhD, professor of environmental epidemiology at the Institute of Public Health. and Tropical Switzerland, the University of Basel, Switzerland – and the head of the Health and Environmental Exposure Unit, the Swiss Tropical and Public Health Institute, the Affiliate Institute of the University of Basel. share with theheart.org | Medscape Cardiology.
“Clinicians may consider noise exposure as an additional risk factor in assessing a patient’s medical history,” he said.
The study was published on November 20 in the medical journal’s online channel European Heart Journal.
Disease design – crossed
Environmental noise exposure contributes to approximately 48,000 new cases of ischemic heart disease annually. Previous research has focused mainly on the long-term effects; short-term effects have not been fully studied, says Professor Röösli.
In particular, he added, it is important to better understand whether noise exposure acts as a risk factor for cardiovascular complications and how the duration of noise exposure modulates that response. necessity.
To investigate this question, the researchers analyzed 15-year-old data from the Swiss National Cohort (SNC) – data that links national census records and overall mortality. Swiss population. The SNC stores personal information as well as household, building and mortality data (including hours and cause of death).
The researchers focused on 24,886 individuals over the age of 30 who died of heart disease, and lived near Zurich airport.
The researchers linked all aircraft movements at Zurich airport between 2000 and 2015 to calculate pre-existing outdoor aircraft noise exposure. Using the disease-crossover design, they matched deaths with up to 4 selected control days within the same month and day of the week. They then separately examined deaths that occurred during the day (7:00 to 23:00) and deaths that occurred at night (23:00 to 7:00).
“This study design is useful for studying the acute effects of noise exposure with high daily variability, such as changing aircraft noise based on weather conditions or flight delays. fly,” lead author Apolline Saucy, a PhD candidate at the Institute of Tropical and Public Health, explained in a press release.
“With this approach to time analysis, we were able to separate the effects of unusually high or low noise levels on mortality from other factors. The bias in this study design will not be lifestyle specifics, such as smoking or dieting,” Saucy said.
The researchers evaluated the associations over a 2-hour exposure time frame before nighttime mortality. For the daytime deaths, they assessed associations at five exposure frames the night before the complication date:
- All night (12:00 – 7:00)
- Late night (19:00 – 23:00)
- Decline in flight traffic due to flight delays (23:00 – 23:30)
- Main Night (23:30 – 6:00)
- Early morning (6:00 – 7:00)
All noise indicators are highest during the evening hours and lowest during the main night.
They also take into account long-term nighttime exposure to road and rail traffic noise at the sites where deaths occur during the year, as well as air pollution and meteorological factors.
Amplified stress response
Of the 24,886 cardiovascular deaths, there were 7641 deaths at night and 17,245 deaths during the day.
About 3% of all deaths (n = 782) were due to aircraft noise (i.e. exposure within 2 hours before death) – an estimate “comparable to cardiovascular mortality factors”. other factors, such as anger, positive emotions, sexual activity and indigestion, and with previous estimates of long-term aircraft noise exposure,” the authors commented. .
Nocturnal noise exposure in the 2-hour frame was significantly associated with all-cause mortality for those exposed to 40 to 50 dB of noise as well as those exposed with noise above 50 dB (difference ratio [OR], 1.33; 95% CI, 1.05 – 1.67; and OR, 1.44; 95% CI, 1.03 – 2.04, corresponding to P trend = 0.01).
These associations were found in patients with heart failure (P trend = 0.05) and were “suggestive” in patients with ischemic heart disease but did not reach clinical significance (P). trend = 0.18).
The mortality rate within the 2-hour exposure time frame was higher in women than in men (OR, 1.13; 95% CI, 1.04 – 1.23; vs OR, 0.98; 95% CI, 0.89 – 1.07), especially for arrhythmias.
Swiss men have a lower risk of death than European men. Those with lower education, lower socioeconomic status, and older age have a higher level of risk.
Notably, those who were divorced had the highest mortality rate (OR, 1.22; 95% CI, 1.00 – 151). Married men had the lowest risk of death (OR, 0.98; 95% CI, 0.87 – 1.11) compared with married women, and married women had a higher risk than women. divorced (OR, 1.22; 95% CI, 1.01 – 1.48).
Röösli explains that noise induces the stress response through the activation of the autonomic nervous system and the hormonal system.
“In addition, this stress response is amplified by sleep problems, which can also be a result of noise exposure,” he said.
Research “Powerful, Innovative”
Comment on research for theheart.org | Medscape Cardiology, Mathias Basner, MD, PhD, MScEpi, professor co-director, Division of Health and Behavioral Regulation, Experimental Psychiatry Unit, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, calls this “one strong, innovative research.”
The use of a large national cohort made the study particularly “robust” and “provided both exposure and association calculations with health data.”
Airplane noise is different from the steady noise on a busy highway. “An intermittent noise, such as an airplane, can trigger an autonomic nervous system response and is considered the trigger event for a death event,” said Basner, who was not involved in the study. people such as a heart attack”.
Also comment on research for theheart.org | Medscape Cardiology, says Thomas Münzel, MD, head of the Department of Cardiology, Johannes Gutenberg University Mainz, Mainz, Germany, “There is now significant evidence to suggest that noise [máy bay] is a cardiovascular risk factor that cannot be changed by the patient or the physician.”
Münzel, who was not involved in the study, suggested that change could be brought about by politicians and the cardiovascular community by “reinforcing, for example, the new noise limits announced in WHO guidance regarding road, airplane and rail noise.”
The study was supported by the Boehringer Ingelheim Foundation and the Heart of Mainz and the DZHK Foundation, Partner Site Rhine – Main, Mainz, Germany. Röösli and co-authors, Münzel and Basma have disclosed no relevant financial relationship.
Eur Heart J. Published online November 20, 2020.
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Reference: Does night-time aircraft noise trigger mortality? A case-crossover study on 24 886 cardiovascular deaths
Translator: Gia Minh
Reviewer: Tran Phuong