TUESDAY, Feb. 12 (HealthDay News) -- People who live near major
airports may be disturbed by the din of aircraft flying overhead
all day, but a new study finds it can also boost their blood
pressure even while they're sleeping.
In fact, the louder the noise, the higher blood pressure will
go, the study found. That finding holds whether the noise comes
from airplanes, passing traffic or other sources, according to the
report in the February issue of the
European Heart Journal.
"We know that noise from air traffic can be a source of
irritation, but our research shows that it can also be damaging for
people's health, which is particularly significant in light of
plans to expand international airports," co-author Dr. Lars Jarup,
from the Department of Epidemiology and Public Health at Imperial
College London, said in a prepared statement.
"Nighttime aircraft noise can affect your blood pressure
instantly and increase the risk of hypertension. It is clear to me
that measures need to be taken to reduce noise levels from
aircraft, in particular during nighttime, in order to protect the
health of people living near airports," Jarup said.
In the study, the British team studied 140 people who lived near
London's Heathrow Airport, as well as airports in Athens, Milan and
Stockholm.
While the volunteers slept, the researchers remotely measured
their blood pressure every 15 minutes. They also analyzed the noise
level in the participant's bedrooms.
Jarup's group found a noticeable increase in blood pressure when
noise levels grew louder than 35 decibels. That amount of increased
noise can occur as an airplane flies overhead, from traffic noise,
or even from someone snoring nearby. The increase in blood pressure
was apparent even when the participant stayed asleep, the
researchers found.
The noise from aircraft increased blood systolic pressure (the
top number in a reading) an average of 6.2 mmHg, and diastolic
pressure an average of 7.4 mmHg, the researchers found. This
increase in blood pressure was also seen from other noise, such as
road traffic, according to the report.
The boost in blood pressure was directly related to the loudness
of the noise, Jarup's group found. In fact, every 5 decibel
increase in airplane noise caused an increase in systolic blood
pressure of 0.66 mmHg. The key factor in increasing blood pressure
was the level of the noise, not its source, the researchers
noted.
One expert believes more studies are needed to see if avoiding
noise can benefit cardiovascular health.
"Elevations in systolic and diastolic blood pressure are
important modifiable risk factors for heart attack and stroke,"
said Dr. Gregg C. Fonarow, a professor of cardiology, at the
University of California, Los Angeles.
This study is consistent with earlier studies, which showed that
environmental noise can significantly increase systolic and
diastolic blood pressure during sleep, Fonarow added.
"Further studies are necessary to determine if avoiding excess
noise during sleep will result in better blood pressure control and
cardiovascular risk reduction in individuals with hypertension,"
Fonarow said.
"The study adds to the literature that noxious and stressful
exposures have adverse cardiovascular consequences," said Dr.
Harlan M. Krumholz, a professor of medicine at Yale University
School of Medicine in New Haven, Conn.
How this finding translates into policy is not quite clear, but
it appears that the adverse effect of noise can be demonstrated by
blood pressure changes, Krumholz said. "What is interesting here is
that it occurred during sleep," he added.
"Whether all people are affected similarly and whether this
response correlates with a higher risk of heart disease is not
clear, but it seems sensible to assume that a noisy environment is
not good for health," Krumholz said.
More information
For more on high blood pressure, visit the
American Heart Association.
