Study links secondhand smoke to artery damage
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January 13, 1998
Web posted at: 5:46 p.m. EST (2246 GMT)
WINSTON-SALEM, North Carolina (CNN) -- A study conducted in the hometown of tobacco giant R.J. Reynolds Tobacco Co. has found that exposure to secondhand cigarette smoke causes potentially life-threatening damage to the arteries.
The study by researchers at Wake Forest University also reaffirmed previous findings that smokers themselves suffer the same risk, and concludes that the damage caused by heavy smoking may be cumulative and irreversible.
"Individuals who are exposed to passive cigarette smoke on a daily basis have more atherosclerosis -- or hardening of the arteries, as measured by ultrasound -- than people who don't," said George Howard of Wake Forest.
The study, which was published Tuesday in the Journal of the American Medical Association, is said to be the first to look at the long-term effects of passive smoke on a large group of nonsmokers.
"The study ... suggests that when a person finishes work in
a smoke-filled office, factory or restaurant, he or she goes
home with more than just the smell of cigarette smoke on their clothes," said researchers from the University of Rochester School of Medicine, who commented on the study.
The Wake Forest study involved 10,914 middle-aged adults who
were examined for the impact of both smoking and exposure to
Increase in progression of atherosclerosis
It found that cigarette smoking was associated with a 50 percent increase in the progression of atherosclerosis compared to people who had never smoked, while past smoking was associated with a 25 percent increase.
Atherosclerosis, the hardening and thickening of artery walls, is the leading cause of death in the United States. It has a number of causes including smoking, obesity, high blood cholesterol levels and physical inactivity, and leads to heart attacks and strokes.
The researchers also found that smokers who quit only reduce their risk by one-half.
"Active cigarette smoking is established by us -- and, really, almost everyone -- as being the single largest risk factor for hardening of the arteries," Howard said.
The study also found that in nonsmokers, exposure to secondhand smoke led to a 20 percent increase in the progression of atherosclerosis.
"The effect of smoking on atherosclerosis progression may be cumulative, proportional to lifetime ... exposure, and perhaps irreversible," the report says.
The study found that damage to the arteries is worse if exposure to smoke is combined with other risk factors such as high blood pressure or high cholesterol levels.
'Not much is passive about passive smoke'
The Rochester researchers, who commented on the study in an
editorial in the same issue of the journal, said previous studies have rarely touched on the effects of secondhand smoke on atherosclerosis.
"Not much is passive about passive smoke," the editorial
said. "However, what is passive is our lack of recognition of
the importance of passive smoke as a cardiovascular disease risk factor, our oversight in not asking patients about this exposure and our lack of advocacy for clean air as a way to help prevent chronic disease."
Said Dr. Basil Margolis, a cardiologist, "I think this is going to add yet more fuel to the argument that smoking in public places and the workplace should be prohibited."
Medical Correspondent Al Hinman and Reuters contributed to this report.