EMBARGOED UNTIL
12:01 AM EDT/Friday, April 17, 2009
Contact: Donna Krupa
Newsroom: (504) 670-4525 or 4526
Office: (301) 634-7209
Cell: (703) 967-2751
dkrupa@the-aps.org
Smoke From Cigarettes,
Cooking Oil, Wood, Shift Male
Cardiovascular System Into Overdrive
NEW ORLEANS—Secondhand tobacco smoke and smoke
from cooking oil and wood smoke affected cardiovascular function of men and
women who were exposed to small doses of the smoke for as little as 10
minutes, according to a study from the University of Kentucky.
The study confirmed
previous findings that tobacco smoke could possibly harm cardiovascular
function. In addition, it extended those findings
by showing that:
-
cardiovascular responses
during brief exposures were similar to those found during longer or
higher-level exposures
-
the response occurs with
different types of smoke (tobacco, cooking oil and wood smoke)
-
men respond to environmental tobacco smoke with a greater
increase in indexes of sympathetic outflow to blood vessels than do
women
The sympathetic nervous system produces the “fight or
flight” response, which drives the heart and blood pressure and may cause
damage if activated too long. Women respond with
a greater parasympathetic response, dubbed “rest and digest,” which acts as
a brake on the heart and blood pressure.
The study, Autonomic
responses of men and women to particulate exposures, was conducted by
Joyce McClendon Evans, Abhijit Patwardhan, Ashwin Jayanthi and
Charles Knapp of the University of Kentucky; Roger Jenkins and Ralph Ilgner
of the Oak Ridge National Laboratory; and Eric Hartman of CustomKYnetics,
Inc. Ms. Evans will present the findings during the 122nd annual meeting of
The American Physiological Society (www.the-aps.org/press),
which is part of the Experimental Biology 2009 conference. The
meeting will take place April 18-22 in New Orleans.
Controlled smoke exposures
Accumulating evidence
indicates that an increase in air pollution is associated with an increase
in heart attacks and deaths. These pollutants, including tobacco and cooking
oil smoke, contain fine particles that evoke responses from heart and blood
vessels indicating effects on their function.
This study briefly exposed
people to low levels of common pollutants and measured their cardiovascular
and cardiorespiratory responses. Forty healthy non-smokers (21 women, 19
men) whose average age was 35 participated in the experiment. The
researchers exposed the participants to secondhand cigarette smoke, wood
smoke or cooking oil smoke in separate trials as they sat in a 10-by-10-foot
environmental chamber. The researchers cleared the air in the chamber after
each trial.
They measured respiratory and cardiovascular function,
including heart rate variability, breathing and blood pressure. These
measures, in turn, gave researchers a picture of how the heart, circulatory
and respiratory systems were reacting to the pollutants.
Results
The study found that, particularly among men, exposure
to smoke changed breathing patterns, raised blood pressure oscillations in
peripheral arteries and shifted control of heart rate toward sympathetic
domination. The sympathetic nervous system becomes active during times of
stress, but can cause harm to the heart and blood vessels if activated too
often or too long.
Women did not have a strong sympathetic response to the
pollutants, a healthier response in the face of frequent exposure. That men
would respond differently is not a surprise: women tend to have stronger
parasympathetic responses, which are more protective of the cardiovascular
system, Ms. Evans said.
These results confirm results from earlier studies, but
with exposures that were at lower levels and for shorter lengths of time.
The study also extended the findings in several ways, including finding that
men and women respond differently.
“I was surprised we got statistically significant
results with this low level of exposure,” Ms Evans said. “If we can detect
these effects with smaller exposures, then the public health hazard from
cigarettes and other particulate exposures may have been underestimated.”
The experimental protocols were reviewed and approved
by the Institutional Review Boards that oversee human studies at both the
University of Kentucky and Oak Ridge National Laboratory.
********
Physiology
is the study of how molecules, cells, tissues and organs function to create
health or disease. The American Physiological Society (APS) has been an
integral part of this scientific discovery process since it was established
in 1887.
Editor’s Notes: To arrange an interview with Ms.
Evans, please contact Donna Krupa at
dkrupa@the-aps.org or (301) 634-7209 before April 17 and at 504.670.4525
or 504.670.4526 April 17-22.
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